Freeplay CM3 --> CM4S

[Lanium]

From SSH, i first made a symbolic link from my home to a directory named /home/pi. This workaround allowed running all the scripts that are hard coded to use that directory without error.

Code:

sudo ln -s ~ /home/pi

I was able to download and compile the very optimized fbcp from here: https://github.com/juj/fbcp-ili9341

Code:

sudo apt-get install cmake
cd ~
git clone https://github.com/juj/fbcp-ili9341.git
cd fbcp-ili9341
mkdir build
cd build
cmake [options] ..
make -j
sudo ./fbcp-ili9341

After running the binary the screen changed from a white screen to duplicate the hdmi.

for the [options] i used the recommended ones except since the CM4S runs faster than the CM3/CM3+ i set the -DSPI_BUS_CLOCK_DIVISOR=8 from 6

Code:

-DARMV8A=ON -DFREEPLAYTECH_WAVESHARE32B=ON -DSPI_BUS_CLOCK_DIVISOR=8 -DDISPLAY_BREAK_ASPECT_RATIO_WHEN_SCALING=ON -DUSE_DMA_TRANSFERS=ON -DBACKLIGHT_CONTROL=ON -DGPIO_TFT_BACKLIGHT=31 -DSTATISTICS=0

This allowed me to not underclock the cpu to 400, however the viewable area of the screen was restricted.

This comment pointed me towards the code to change: https://forum.freeplaytech.com/showthrea...10#pid8610

Code:

In 'freeplaytech_waveshare32b.h': (also important as unmodified juj driver have not access to Freeplay screen config)
DISPLAY_NATIVE_COVERED_TOP_SIDE is left border of the screen
DISPLAY_NATIVE_COVERED_LEFT_SIDE is top border of the screen
DISPLAY_NATIVE_COVERED_RIGHT_SIDE is bottom border of the screen
DISPLAY_NATIVE_COVERED_BOTTOM_SIDE is right border of the screen